The membrane bound forms of the coat proteins of the filamentous bacteriophages fd and Pfl will be studied by high resolution NMR spectroscopy. The proposed research is highly focused on obtaining structural and dynamical information about these proteins from one- and two-dimensional 1H and 15N NMR experiments. Preliminary 1H two-dimensional correlated and NOE spectra show many cross-peaks, including those between N-1H amd CAlpha - 1H resonances, indicating tht proton connectivities can be mapped out on both through-bond and through-space bases. The secondary structure of the immobile protein segments will be determined from these 1H NMR experiments. Well resolved 15N spectra enable the relaxation parameters, especially the heteronuclear NOE, to be used to describe protein dynamics. The availability of specifically 15N labelled proteins, the use of heteronuclear two-dimensional correlations, and the generation of site specific mutations will assist in making both 1H and 15N resonance assignments. The properties of the coat proteins in membrane environments will be compared to those in the assembled virus.